The present invention relates to a device for the distribution of a fluid under pressure, such as an expander for gas under pressure, provided with one or several built-in manometers, usable particularly in the field of welding or medicine.
Conventionally, to indicate the pressure of a fluid, it is usual to use a manometer. Thus, manometers adapted to be mounted on expanders for gas or other fluids to indicate the pressure of said gas or fluid, for example before and after expansion, are conventionally fixed on the expander by means of a screwed connection, also called a connecting ferrule, as set forth in the standard EN562.
So as to be able to ensure on the one hand the sealing between the expander and the manometer and, on the other hand, the. correct positioning or indexing of the manometer, so as to be able to read the indication which it gives, it is also conventional to provide between the end of the screw thread carried by the connection ferrule and the bottom of the tapped recess of the manometer body, adapted to receive said ferrule, a deformable ring constituted for example of aluminum or plastic material.
During the operation of mounting the manometer on the body of the expander, said manometer is first screwed with a torque sufficient to ensure sealing, then with a supplemental torque adapted to deform the above-mentioned ring, so as to reach the required angular position to read it, which is to say to index said manometer.
An analogous technique comprises the use of a conical screw-threaded ferrule provided with a film of deformable material, for example a strip of TEFLON or of tow.
According to still another technique, it is possible to secure the manometer on the expander by means of screw-threaded nozzle or, as the case may be, by compression of a flat joint with the aid of a floating nut.
However, these different ways of securement have a certain number of drawbacks.
Thus, the technique of the deformable ring, which is in widespread use, has at least four major drawbacks, in particular these:
it implies the transmission of a relatively great torque to the connecting ferrule of the manometer and hence requires arranging between the screw-threaded portion of the connecting ferrule and the housing of the manometer, a portion of square or hexagonal cross-section to which will be applied the gripping torque by means of a flat key or similar gripping device, which moreover implies providing a sufficient space between the lower end of the housing of the manometer and the upper surface of the body of the expander to permit the passage of said gripping key, during mounting or unmounting of the manometer on the expander. Such requirements therefore limit the possibility of designing new expanders, in particular when it is desired to decrease their size and to increase their mechanical efficiency. Moreover, this type of mounting gives rise to increase of cost of mounting and/or unmounting the manometer.
it requires the use of deformable materials, such as aluminum or plastic, which are incompatible with certain gases, such as for example oxygen.
it poses problems of sealing under extreme temperature conditions because of the expansion of the assembly, flow or modification of the mechanical characteristics of the ring, for example during temperature variations from xe2x88x9240xc2x0 C. to +60xc2x0 C.
it requires delicate maintenance, particularly upon dismounting, because it is generally difficult to remove the ring after deformation.
Moreover, the solution consisting in using a tapped nozzle permits fixing the manometer on the expander without requiring a screwing operation or the like, as used in expanders of the MONOBLOC 3 type sold by LA SOUDURE AUTOGENE FRANCAISE.
However, this solution cannot be considered as ideal, to the extent that it requires, on the one hand, that the manometer be held during its mounting and on the other hand that access be provided to the rear of the body supporting the manometer so as to be able to mount the tapped nozzle, which limits the possibilities of design of new expanders.
The object of the present invention is thus to provide a solution to the above-mentioned problems, whilst improving the safety and mechanical efficiency of the expanders.
The present invention thus relates to a device for the distribution of fluid under pressure, such as an expander of fluid under pressure, comprising at least one body provided with at least one manometer comprising a housing and a connection ferrule, said connection ferrule being inserted in a recess provided in the body, characterized in that:
said body moreover comprises at least one passage communicating with said recess,
said connection ferrule comprises at least one recess, and
at least one connection means is inserted in at least one portion of at least one passage of the body and in at least one portion of at least one recess of the connection ferrule, so as to permit the securement, at least temporarily, of said manometer on said body.
As the case may be, the device for distributing fluid under pressure according to the invention comprises one or several of the following characteristics:
at least one recess is provided in the lateral peripheral wall of the connection ferrule;
the connection ferrule comprises several recesses, in that the body comprises several passages communicating laterally with said recess, and in that at least one connection means is inserted in at least one portion of at least one of the passages and in at least one portion of at least one of the recesses;
the connection ferrule moreover comprises at least one sealing means, preferably one or several O-rings;
the sealing means is arranged between at least one recess and the distal end of the connection ferrule and/or in that the sealing means is inserted in a circular peripheral throat provided in the lateral peripheral wall of the connection ferrule;
the connection means is of elongated shape, preferably, and is chosen from keys, pins, rods, screws, cotters or other similar means;
the latter peripheral wall of the connection ferrule is free from screw-threading and/or the peripheral wall of the recess is free from tapping;
at least one supply passage for fluid under pressure opens through an opening in the bottom of the recess of the body;
at least one supplemental passage establishes communication between the recess and the atmosphere and opens through the side wall of the recess;
at least one supplemental recess, comprising control means for the circulation of fluid under pressure entering the recess through the opening, is provided in the body between the bottom of said recess and the supply passage;
it is chosen from expanders for fluid under pressure, particularly expanders or valve/expander ensembles for gas under pressure.
The invention moreover relates to a manometer adapted to be provided for a device according to the invention, said manometer comprising a housing and a connection ferrule, characterized in that said connection ferrule comprises at least one recess provided in its peripheral side wall.
Preferably, the connection ferrule of the manometer moreover comprises at least one circular peripheral throat adapted to receive a sealing means, such as an O-ring, said circular peripheral throat being arranged between at least one recess and the distal end of the ferrule.
The invention also relates to an expander for fluid under pressure comprising at least one body and at least one recess provided in the body and adapted to receive at least one portion of a connection ferrule of a manometer, characterized in that said body comprises at least one passage communicating laterally with said recess.
Moreover, the invention also relates to a cylinder of fluid under pressure provided with a fluid distribution device, in particular an expander, such as those mentioned above.